Some core things stay the same in housing design – but not energy efficiency

During the time we spent constructing CSR House, a great deal of work went into finding the most effective products to create the ultimate Australian family home – in terms of comfort, aesthetics and efficiency.

While it’s a necessary challenge to look forward in our building industry, the completion of the CSR House also provides a useful opportunity to look back at how far the Australian construction industry has really come over the past 100 years.

Five decades ago CSR built another house, also in Sydney, and also to demonstrate the way in which CSR’s innovative products could be used together to build a comfortable and modern family home.

Located on Princes Highway, Kirrawee, its construction was announced in the CSR newsletter with these words: ‘The cottage is simple in design and is intended to show how CSR building products can be used to advantage in a low-cost home that would have an appeal to a young Australian family.’ After 50 years it’s quite remarkable to think such a description could just as easily have been used in this newsletter to describe the latest incarnation of CSR House.

While some of the ‘hero’ products used in today’s CSR House include Monier SolarTile, Viridian glass, Bradford insulation and Odyssey, the latest Edmonds ventilation system, the technologies incorporated in 1957’s version were no less ground breaking at the time.

Gyprock provided ‘a smooth, jointless surface for all wall and ceiling areas’ while Cane-ite was used under the Fibrock sidings to improve temperature control and limit noise. Timbrock, used extensively throughout the house, was described in an advertisement at the time as ‘natural wood made better’.

Like today, a crucial factor cited in advertisements was the way in which the products worked together, bringing to the fore one of CSR’s unique selling points: the breadth of the range gives us an opportunity to really examine how well our products perform when combined.

A century ago, another family home was built in Sydney, which also had a connection to CSR. It was none other than CSR Innovation General Manager, Ray Thompson’s grandparent’s house, located in Crane Street, Concord, NSW. While the house itself no longer stands, we’ve had the opportunity to use the original plans to develop a working model of the building, looking at how the different aspects would have complemented each other, and how it would have been run.

What can we learn from the lessons of 100 years of CSR housing?

While an emphasis on comfort, style and affordability remains, what has changed is the arrival of energy efficiency as a serious consideration. While past CSR homes were also planned to have a low cost of construction, little if any thought was given to the cost of actually running them.

On today’s reckoning the 84 square metre Concord house would have a Zero energy star rating; while even the 78 square metre Kirrawee home would score only 0.6 stars. By way of comparison, CSR House (240 square metres) scores 8 stars.

To put this into more practical terms, consider the impact on energy bills. We calculated the cost of heating and cooling each of the three houses, at today’s electricity prices. The Concord home would come in at $2319 each year, while the 0.6 Star Kirrawee house would be just over $1500.

Heating and cooling energy costs for the much larger CSR House today however would be only $184 – a huge saving, and a life-changing amount of money to have in the bank each year for many Australian families. To put this further into context, cast your mind back to the ‘McMansions’ we saw pop up all over the country in the 1990s, before energy efficiency was seriously appreciated as an issue. The cost to run such a large and inefficient house (230 m2 and 1.6 Stars), just in terms of heating and cooling, would be a staggering $3,460!

It’s reassuring to discover just how well CSR House measures up against its predecessors. While an emphasis on creating a comfortable, attractive and cost-effective family home remains, the new focus on energy efficiency means that our efforts now are cheaper to run and better for the environment, by quite some margin. Who knows what the next hundred years will bring …